X-Git-Url: http://git.euphorik.ch/?p=Scala.git;a=blobdiff_plain;f=Assignment_06%2Fsrc%2Fmain%2Fscala%2FAnagrams.scala;fp=Assignment_06%2Fsrc%2Fmain%2Fscala%2FAnagrams.scala;h=e52912447851b71ad2ecc792504fa3f7472f3abb;hp=0000000000000000000000000000000000000000;hb=6c413508bbba63f2421fd57d87eba4266c5beca0;hpb=3caf6fced99f7fe7d910dfdc3baa9ade89145848

diff --git a/Assignment_06/src/main/scala/Anagrams.scala b/Assignment_06/src/main/scala/Anagrams.scala
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+package anagrams
+
+/**
+ * Sentence anagrams generation
+ * MSE course, T-AdvPrPa course
+ */
+object Anagrams {
+	/**
+	 * Types definitions
+	 */
+	type Word = String
+	type Occurrences = List[(Char, Int)]
+	type Sentence = List[Word]
+
+	/**
+	 * The dictionary is simply a sequence of words.
+	 * It is predefined and obtained as a sequence using the utility method `loadDictionary`.
+	 */
+	val dictionary: List[Word] = loadDictionary()
+
+	/**
+	 *  Question 1 : converts the word into its character occurrence list.
+	 *
+	 *  For instance,
+	 *  wordOccurences("abcd") gives List(('a', 1), ('b', 1), ('c', 1), ('d', 1))
+	 *  wordOccurences("aabcddd") gives List(('a', 2), ('b', 1), ('c', 1), ('d', 3))
+	 *
+	 *  Note: the upper case and lower case version of the character are treated as the
+	 *  same character, and are represented as a lower case character in the occurrence list.
+	 *  The list is sorted alphabeticaly.
+	 */
+	def wordOccurrences(w: Word): Occurrences =
+		w.toLowerCase().groupBy(identity).toList.map{ case (_, letters) => (letters(0), letters.length) }.sortWith((a, b) => a._1 < b._1)
+
+	/**
+	 * Question 2: Valid words
+	 *
+	 * The `dictionaryByOccurrences` is a `Map` from different occurrences to a sequence of all
+	 * the words that have that occurrence count. This map serves as an easy way to obtain all the anagrams of a word given its occurrence list.
+	 */
+	lazy val dictionaryByOccurrences: Map[Occurrences, List[Word]] =
+		dictionary groupBy (w => wordOccurrences(w))
+
+	/**
+	 * Question 3: Returns all the anagrams of a given word
+	 */	
+	def wordAnagrams(word: Word): List[Word] =
+		dictionaryByOccurrences get wordOccurrences(word) match {
+			case Some(words) => words
+			case None => List()
+		}
+	
+	/**
+	 * Question 4: Returns all the subsets of an occurrence list
+	 */
+
+	/**
+	 * Generates all the subsets of a set
+	 */
+	def combinations(occurrences: Occurrences): List[Occurrences] = ???
+	
+	/**
+	 * Question 5: remove occurrences from x that are in y
+	 */
+	def subtract(x: Occurrences, y: Occurrences): Occurrences = ???
+	
+	/**
+	 * Question 6 - Generate sentence anagrams
+	 */
+	
+	/** Converts a sentence into its character occurrence list. */
+	def sentenceOccurrences(s: Sentence): Occurrences = ???
+	
+	def sentenceAnagrams(sentence: Sentence): List[Sentence] = ???
+
+}